Telephone



(No Model.)

W. A. WEST.

TELEPHONE.

No. 329,983. Patented Nov. 10, 1885.

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UNITED STATES PATENT OFFICE.

WILLIAM A. WEST, OF BELLEFONTAINE, OHIO, ASSIGNOR TO THE WEST TELEPHONE COMPANY, (LIMITED,) OF KENOSHA, WISCONSIN.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No.329,983, dated November 10, 1885.

Application filed November 20, 1884. Serial No. 148,449.

To all whom it may concern.-

Be it known that I, WILLIAM A. WEsT, a citizen of the United States, residing at Bellefontaine, in the county of Logan and State of Ohio, have invented certain new and useful Improvements in Telephonic Telegraphs, of which the following is a specification.

The main object of my invention is to control the vibrations of the movable contact in telephones, intending by movable contact that moving part which, for the purpose of completing the circuit in which it is included, contacts with the contact carried by the diaphragm. If, for instance, we suppose apendant or freely-moving contact-piece which normally rests against or makes contact with a r1 g1d contact carried by the diaphragm, the v1brations of the diaphragm, due to the soundwaves which strike it, will, through the intermedlary of the rigid or fixed contact, put the movable contact-piece into vibration.

It is with a view to controlling this vibratory movement of the movable contact that my invention has mainly been devised.

I find that the result aimed at can be accomplished by exerting upon the pendant an attractive force, which, called into action when the movable contact moves in a direction away from the fixed contact, influences at that time the contact to move in the opposite direction that is to say, in a direction to reestablish contact between the two contact-pieces; and it is preferred to apply this force in such manner that it shall, as respects the movable contact-piece, be repellent or attractive, accordmg to the conditions of the circuit in which the movable contact-piece is includedthat is Y to say, so long as the contact between the two (No model.)

the preferred form of apparatus Ihave devised for the purpose of effectuating said method.

In the drawings accompanying this specification, Figure I is a rear elevation of a transmitter constructed in accordance with my invention. Fig. II is avertical central section of the same. Fig. III is a longitudinal section on line III III, Fig. Il. Fig. IV is a rear elevation of a modification hereinafter referred to. Fig. V is a diagrammatic representation ofa telephone-circuit containing my improved transmitter and receiver.

Within the frame 1 the transmitting-diaphragm 7 is fixed by its edges so as to allow freedom of motion to its center. A rubber band, 8, is preferably employed as a seat on both sides of the'diaphragm. Fixed opposite to the center of the diaphragm is the perforated softiron core 9; which is wound with the primary and secondary wires 10 11 of an in ductorium. Said Wires are wound in opposite directions upon the core, so that their poles will coincide. Fixed to the center of the diaphragm is a rigid needle, 12, of any desired conducting material, one end of which rests against a carbon or other suitable contact-button, 13, supported on the lower end of a pendant, 14, preferably of soft iron.

The needle is what I have termed the fixed contact, and the pendant is the movable contact. The latter is capable of freely vibrating,and is so supported by its trunnion-screws 15,working in a bracket, 16,fixed to the frame, as to hang vertically, and in this position to contact, without appreciable pressure, with the end of the needle.

The primary wire 10 of the induction-coil is,in the illustration given in the drawings, in a local circuit, in which are included also the diaphragm and the fixed and movable contactpieces, the course of the circuit being from battery 4., through diaphragm, needle, pendant, and primary 10 of the induction-coil to the receiver 19, and thence back to battery. The circuit, normally, is closed, and consequently the core 9 is magnetized,and the pendant is attracted thereby. If the helix 10 be wound so as to make a north pole of that end of the core next to the pendant, the latter will of course be of an opposite polarity so long as it is under the influence of the core.

Under the arrangement thus far described the vibration of the diaphragm, caused by speech or other influences, will, through the needle, impart vibratory movement to the freely-swinging pendant, with the effect of causing the two contacts to recede from and approach each otherso long as the'v ibrations' swinging pendant,with the result ofproduci ng similar irregularityin theimpulses transmitted To correct this trouble, I

over the circuit. make use of a permanent magnet or its equivalentsuch as a permanently or constantly I energized electro-magnetso positioned and arranged that at the times when the pendant or movable contact recedes from the fixed contact and is freed from the magnetic influence of the core 9 (whose attractive power over the pendant is lost by the disturbance of the circuit due to the recession of the contacts from each other) it will, by its attractive force, tend to draw the pendant or movable contact in a direction to restore the normal condition of the circuit; and this magnet is arranged also so that at other times it will exert a repellent force to about offset the attractive force of the electro-magnet 9, thus in effect leaving the pendant or movable contact as free to move as though neither magnet were there. In the arrangement shown in the drawings for bringing about this result a permanent magnet,18, is employed, fixed to the main frame by a setscrew, 17. This magnet-preferably of horseshoe formis so placed as to present to the pendant a pole of similar polarity to that of the pendant. For instance, if, as already supposed, the pole of core 9 presented to the pendant be N when the core is magnetized, the pendant will be of S polarity when the circuit is normal. Consequently the S pole of the permanent magnet 18 should be presented to the pendant. Care should be taken to adjust the magnet so that its repellent force upon the pendant will not more than neutralize or offset the attractive force of the core 9, and this can easily be determined byexperiment. If the permanent magnet should be placed too near the pendant-in other words, if the repellent force should exceed the otherthe permanent magnet would alternately repel and attract the pendant, with the effect of alternately making and breaking contact between the pendant and the needle, thus putting the pendant into rapid vibration,'and virtually making a rheotome of the instrument.

The secondary coil 11 of the transmitter is in the main-line circuit, as shown. Impulses sent over the line from a distant station act, through the coil 11, to disturb the equilibrium of the magnets 9 and 18, thus causing corresponding vibrations of the pendant, which,

through the local circuit, are conyeyed to the receiver 19, whose primary coil isin said local circuit. To intensify this'action, I prefer to surround the primary coil 21 of the receiver with a secondary helix, 22, included in the main circuit, as shown. This, however, is not indispensable, for the receiver may be inthelo'caljcircuitlonly. In anyevent, however, my transmitter is interposed, as indi cated, between the original transmitter and the receiver, with its primary coil in circuit withthe primary coil of the receiver.

For long'lines on which great confusion of the messages is caused by induction, I have found'it best to'shu'nt to ground, as shown at 28,all"the'original current received from line,

depending upon the induced changes in the current of the .local'circuit alone toaffect the of carrying my improvement into efi'ect. I

do not wish to be understood, however, as restricting 'myself to the precise details herein set forth, inasmuch as the same can be varied considerably without departure from'this-invention. I can dispense with the magnet 18, and can make the pendant itself the permanent magnet. Insuch case it should be provided with a pivoted or otherwise suitably-arranged keeper, 3, for adjusting its strength'relativelyto that of the magnet 9, so as'to obtain as nearly as practicable an equilibrium of forces between'the two so'long asthe local circuit is normal. I prefer, however, the arrangement shown inFigs. I, II,and III of the drawings.

What I claim herein as new andof my'own invention isv 1. Thecombination, with the fixed and movable contacts and electro-magnet and circuit in which said'contacts and electro-magnet are included, of acontrolling-magnet which, when the movable contact during its vibratory movement recedes from the fixed contact, tends, by its attractive force, to draw the 'saidmovable contactin the opposite direction, substantially as and for the purposeshereinbefore set forth.

2. The combination, with the fixed and movable contacts, the electro-magnet, and the cir- For'instance, as shown inv Fig. IV,

IIO

able contacts, the electro-magnet having a secondary coil in the main-line circuit and a primary coil in a local circuit, a controlling magnet for influencing the movable contact, substantially as described, and a receiver provided with an inductorium, consisting of a primary coil included in said local circuit and a secondary coil included in said main-line circuit, substantially as and for the purpose hereinbefore set forth.

- \V. A. WEST. Witnesses:

OOTAVIUS KNIGHT, HARRY E. KNIGHT. 

